By Mateusz Rabiega

May 20 (Reuters) - Euronext ENX.PA is prepared to respond if market demand for round-the-clock trading emerges, the exchange operator's chief executive said on Tuesday, though he remained cautious on whether there was enough appetite for 24/7 equity trading.

Exchanges are grappling with the growth of cryptocurrencies and other assets unrestricted by traditional opening hours and technology that has raised expectations, particularly among retail traders, of being able to trade anytime, anywhere.

"We are here to facilitate trading. If there is an appetite of the market to go to 24/7, we will work for it," Euronext CEO and Chairman Stéphane Boujnah told Reuters.

He said that Euronext, which on Tuesday reported another quarter of double-digit growth, is working on a "few ideas" for digital assets, but warned that fully continuous trading would face practical constraints, particularly in processing of trades.

"It's not a gym club that can be open 24/7. It's a bit more complex," Boujnah said.

Euronext operates a network of bourses spanning Paris, Amsterdam, Brussels, Dublin, Lisbon, Milan, Oslo and most recently Athens.

Continental European bourses trade from 0900 to 1730 CET, broadly aligned with Frankfurt, Milan and Madrid, while London's LSEG LSEG.L opens at 8 a.m. local time.

German exchange operator Deutsche Boerse DB1Gn.DE last month warned against 24/7 trading, even as some of its U.S. counterparts, including Nasdaq NDAQ.O and CME CME.O, gear up for the move.

Boujnah linked the debate over round-the-clock trading to the rise of younger retail investors who began trading crypto-assets on mobile phones and could later expand into other asset classes.

"We're already observing that part of the growth of the retail market comes from young investors (but) for the moment, the demand for equity is still relatively limited," he said.

Asked where extended trading might emerge first, Boujnah said digital assets were likely to lead, with other assets potentially coming before ordinary equities.

"I think fixed income might be a better candidate than securities," Boujnah said, adding that markets would likely start with indices or exchange-traded funds.